Surgical burr

ABSTRACT

A method includes processing a first material using a working part having a working device and a prevention device, and using the prevention device to simultaneously prevent damage to a second material adjacent the first material. A method of processing a first material includes arranging a prevention device in a first position to prevent a working part having a working device and the prevention device from processing first and second materials, and arranging the prevention device in a second position to allow the working device to process the first material while the prevention device simultaneously prevents damage to a second material adjacent the first material.

TECHNICAL FIELD

The present disclosure relates generally to processing of material; andmore specifically, to a surgical burr.

BACKGROUND

Conventionally, various devices have been used for shaping of objects,such as cutting, drilling, milling, sawing, polishing and/or grinding.For instance, these devices may include burrs, drill bits, saw bladesand cutting disks. Typically, such devices find applications incarpentry, machining, plastics industry and medical sector. Generally,the shaping and processing of the objects require immense control ofoperator over the hand-held device. Further, targeted action of thedevice is crucial to minimise unintended damage, especially in medicalapplications.

The shaping and processing of hard tissues in the medical sectorprimarily comprises processing of bones or cartilages of a patientundergoing surgery. While soft tissues, such as blood vessels or nerves,can be located in proximity to the processed hard tissue, surgicaldevices may cause accidental damage to the soft tissues of the patient.For instance, surgical devices may cause damages such as dural tears inspinal surgery, facial nerve paralysis during ENT surgery(ear-nose-throat surgery) or lingual nerve paralysis during dentalprocedures.

Subsequently, the damage to the soft tissues may cause swelling, pain,numbness, bleeding and several other complications. Additionally, thedamage to the soft tissues may prolong the recovery of the patient.

One possible tool used to perform a surgical procedure is a burr. A burrgenerally consists of a head formed from rigid material, typically metaland tungsten carbide. There typically exists two types of burrs, cuttingburrs and grinding burrs. A cutting burr has a head shaped to have anumber of flutes. The flutes are formed to define tissue cutting edges,and each flute has a rake surface and a clearance surface. The rake andclearance surfaces meet to form a cutting edge that extends along thelength of the flute, as is shown in more details in the Figures below.In other words, the rake surface is a face in front of the cutting edgewhich shaves the material and the clearance surface is the surfacebehind a cutting edge which extends toward an adjacent flute. A grindingburr has a head having a surface typically coated with an abrasivecoating, such as diamond or hard carbon coating.

Furthermore, in a burr, a shaft extends rearwardly from the head. Thefree end of the shaft has a feature that facilitates locking the shaftto a powered handpiece. The actuation of the handpiece results in therotation of the burr. During a surgical procedure, the burr head isplaced against a surgical site where a section of tissue is to beremoved, i.e. processed. The rotating cutting edges typically excisetissue away from the surgical site, while the burrs can also be used forprocessing foreign objects, such as implants, within the body. Burrs ofvarious shapes and sizes are used in procedures such as orthopedicsurgery, neuro and spinal surgery, ear, nose and throat surgery and inother surgical procedures in which a sub-procedure is to selectivelyremove a section of tissue.

In patent document U.S. Pat. No. 5,876,405, titled “Perforator”, thereis described a drill bit with a centrally disposed sharp guide pin topenetrate a material (such as, a bone structure), while the drill bit isa hollow cylindrical wall with cutting edges formed in its bottom end toremove/cut a bone plug after drilling is complete. Therefore, thedocument does not provide a method to prevent unintended drilling ofmaterial by the sharp cutting edges of a conventional twist drill bit,which are located at the tip of the drill bit.

A burr is thus different from a hollow drill bit, as having a head inburrs differentiates it from such hollow drill bit. A hollow drill bithas cutting edges in its bottom side, which is not the case for a burr.In a twist drill bit, spiral flutes are ground in to the body of theshaft, and the flutes at the tip form cutting edges on the bottom end,not on the circumference of the drill bit. In a burr, in case there areflutes, they form cutting edges on the circumference of the burr head.Furthermore, the geometry and application of drills and burrs aresubstantially different. Burrs are used for milling and grinding, i.e.removing material with a rotary cutter from a workpiece by advancing inany direction (as cutting occurs on the circumference of the burr),while drill bits are used for drilling, i.e. removing material alongtheir rotation axis (as drilling occurs at the bottom end of the drillbit). A further difference is that a burr removes material from amaterial to be processed, instead of making a hole into the material asa drill bit does.

In recent past, advances have been made to improve surgical devices suchas high-speed drills and ultrasonic cutting devices. However, there hasnot been a substantial change in the surgical devices to minimiseunintended damage to the surrounding tissues. For example, the risk ofdamaging soft tissues during the processing of hard tissues is stillprevalent. Additionally, the ultrasonic cutting devices requirepurchasing completely new equipment and also require training of a newtype of surgical procedure, which is inconvenient for the user.

Various industrial tools such as table saws or disc cutters may presenta risk for the user, such as for the user's fingers or hands. Differentprotection means exists, but it may still be beneficial to try toimprove these safety devices.

Therefore, in light of the foregoing discussion, there exists a need toovercome the aforementioned drawbacks associated with conventionaldevices for processing of object.

SUMMARY

The present disclosure seeks to provide a surgical burr for processingof a material. The present disclosure also seeks to provide a solutionto the existing problem of unintended damage caused to soft tissuesduring processing of hard tissues. An aim of the present disclosure isfurther to provide a solution that overcomes at least partially theproblems encountered in prior art, and provides a safe, precise andreliable burr to achieve better control, safety and targeted action forprocessing of a material in medical applications. A still further objectis to decrease chattering of the burr when in use.

In one aspect, an embodiment of the present disclosure provides asurgical burr comprising

prevention means;

attachment means; and

a working part comprising at least one working means for processing of amaterial selected from a bone, a cartilage, a calcified tissue, a toothand a foreign object within a patient body, wherein the working means isselected from a grinding surface and flutes defining cutting edges;

wherein the prevention means is configured to have

a first position in which it is arranged to at least partially preventthe working means from processing the material, when a force applied tothe prevention means is less than a predetermined amount of force, and

a second position in which it is arranged to allow the working means toprocess the material, when the force applied to the prevention means isequal or higher than the predetermined amount of force.

Embodiments of the present disclosure substantially eliminate or atleast partially address the aforementioned problems in the prior art,and enables safe and targeted processing of a material.

Additional aspects, advantages, features and objects of the presentdisclosure would be made apparent from the drawings and the detaileddescription of the illustrative embodiments construed in conjunctionwith the appended claims that follow.

It will be appreciated that features of the present disclosure aresusceptible to being combined in various combinations without departingfrom the scope of the present disclosure as defined by the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The summary above, as well as the following detailed description ofillustrative embodiments, is better understood when read in conjunctionwith the appended drawings. For the purpose of illustrating the presentdisclosure, exemplary constructions of the disclosure are shown in thedrawings. However, the present disclosure is not limited to specificmethods and instrumentalities disclosed herein. Moreover, those skilledin the art will understand that the drawings are not to scale. Whereverpossible, like elements have been indicated by identical numbers.

Embodiments of the present disclosure will now be described, by way ofexample only, with reference to the following diagrams wherein:

FIGS. 1, 2, 3, 4 and 5 are different views of a surgical burr, inaccordance with an embodiment of the present disclosure;

FIG. 6 is a cross-sectional view of the surgical burr of FIG. 5 alongB-B′, in accordance with an embodiment of the present disclosure;

FIG. 7 is an enlarged view of an encircled section of the surgical burrof FIG. 6, in accordance with an embodiment of the present disclosure;

FIGS. 8, 9 and 10 are cross-sectional views of the surgical burr of FIG.5 along C-C′, in accordance with various embodiment of the presentdisclosure;

FIG. 11 is a perspective view of a surgical burr, in accordance withanother embodiment of the present disclosure;

FIG. 12 is a cross-sectional view of the surgical burr of FIG. 11 alongF-F′, in accordance with an embodiment of the present disclosure;

FIGS. 13, 14, 15 and 16 are schematic illustrations of the surgical burrof FIG. 1 in utilized states, in accordance with an embodiment of thepresent disclosure;

FIGS. 17, 18 and 19 are views of a surgical burr in accordance with anembodiment of the present disclosure;

FIGS. 20 and 21 are perspective views of a surgical burr, in accordancewith different embodiments of the present disclosure;

FIGS. 22 and 23 are different views of a surgical burr, in accordancewith an embodiment of the present disclosure;

FIGS. 24 and 25 are different views of a twist-drill, in accordance withan embodiment of the present disclosure;

FIG. 26 is a front view of an oscillating saw blade, in accordance withan embodiment of the present disclosure;

FIGS. 27 and 28 are different views of a saw, in accordance with anembodiment of the present disclosure; and

FIG. 29 is a cross-sectional view of a surgical round burr perpendicularto its central axis, illustrates rake and clearance surfaces.

In the accompanying drawings, an underlined number is employed torepresent an item over which the underlined number is positioned or anitem to which the underlined number is adjacent. A non-underlined numberrelates to an item identified by a line linking the non-underlinednumber to the item. When a number is non-underlined and accompanied byan associated arrow, the non-underlined number is used to identify ageneral item at which the arrow is pointing.

DETAILED DESCRIPTION OF EMBODIMENTS

The following detailed description illustrates embodiments of thepresent disclosure and ways in which they can be implemented. Althoughsome modes of carrying out the present disclosure have been disclosed,those skilled in the art would recognize that other embodiments forcarrying out or practicing the present disclosure are also possible.

In one aspect, an embodiment of the present disclosure provides asurgical burr comprising

prevention means;

attachment means; and

a working part comprising at least one working means for processing of amaterial selected from a bone, a cartilage, a calcified tissue, a toothand a foreign object within a patient body, wherein the working means isselected from a grinding surface and flutes defining cutting edges;

wherein the prevention means is configured to have

a first position in which it is arranged to at least partially preventthe working means from processing the material, when a force applied tothe prevention means is less than a predetermined amount of force, and

a second position in which it is arranged to allow the working means toprocess the material, when the force applied to the prevention means isequal or higher than the predetermined amount of force.

The present disclosure provides a surgical burr for processing ofmaterial. A primary advantage of the device is that when used to processhard tissue, adjacent soft tissues are protected, thanks to theprevention means. Indeed, the device substantially lowers the risk ofprocessing of unintended objects adjacent to the object undergoingprocessing, such as soft tissue adjacent to a hard tissue beingprocessed (for example drilled). The device also enables an operator toexercise better control over the processing of the object. Indeed, theprevention means significantly increases the controllability as itprevents the cutting tool from unwanted and/or excessive penetration tothe work material. In other words, it does not allow a suddenpenetration of the tool to the work material. When that happens, thetool starts to aggressively vibrate (called chattering) and sometimesthe tool goes out of control (jumping). Besides that, the preventionmeans allows the operator to adjust the depth of cut according to theamount of the pushing force he/she applies. This increase the precisionof cut. Consequently, the device achieves precise processing on adesired portion of the object. Therefore, a device which relates to amedical sector, provides safer operation and significantly reduces riskof soft tissue damage in surgical operations. Also, the device enablesprocessing of the object in a time efficient manner. Additionally, thedevice is adaptable according to the type of processing the objectrequires, i.e. adaptable to conventional and existing shaping andprocessing devices, irrespective of their type. Indeed, the “shaping andprocessing” in this specification relates to all kinds of working ofhard tissues, such as cutting, grinding, milling, drilling, polishing,sawing and so on, while in connection with the embodiment of a surgicalburr, processing means cutting, milling and grinding. Furthermore, inthis specification, the term “working surface” relates to the part ofthe working part that actually processes the object, and it can be onlya part of the working part or in some cases, the whole of the workingpart can be the working surface.

The present disclosure provides a surgical burr that can be made inseveral different manners, some of which are explained in more detailbelow. A main feature of the device is that the prevention means has twodifferent positions, a first position and a second position. In thefirst position, the prevention means protrudes from the working part toat least partly, preferably fully, prevent the working means fromprocessing the material. This first position is the one the preventionmeans takes when a force applied to it is less than a predeterminedamount of force. This means that the user will need for example to pressthe device against the material to be processed in order to start theprocessing, i.e. to overcome the limit of force required. The secondposition of the prevention means is the position in which it retracts toallow the working means to process the material. This position is takenby the prevention means when the force applied to it is equal or higherthan the predetermined amount of force. The predetermined amount offorce thus forms a limit which defines the position of the preventionmeans. The prevention means may be actioned into its first position byan attachment means, for example by means of an inner part, centrifugalforces, or the outer part deformation (elastomeric or flexible movingpart). These different embodiments will be explained in more detailbelow.

The surgical burr comprises prevention means for preventing the workingmeans from processing the material. The prevention means is thus amechanism, that can have one or more parts. For example, the preventionmeans may consist of an outer moving part and an inner spring (forexample a canted coil spring or an elastomer functioning as a spring).Alternatively, the prevention means may consist of a moving part whichhas an outer and an inner portion (for example an integrated spring andring), either as integral parts or as separate parts. Still further, theprevention means may consist of a resilient part attached to an outersurface of the working part, for example flaps or elastomeric sections.In this context, by the term resilient are meant parts made of amaterial that is capable of changing shape, for example by bending orcompressing under force (such as pressure) and to return to its originalshape once the force is no longer applied on the part.

According to an embodiment, the prevention means is arranged to protrudefrom the working part in its first position and to retract from theworking means in its second position. According to another embodiment,the prevention means is arranged, in its first position, to push softtissue away from the cutting edge, and, in its second position, to allowthe working means to be in contact with hard tissue.

The prevention means is/are thus configured to have two differentpositions depending on the force applied to the prevention means, whenthe working part is interacting with the material to be processed. Thereare different forms of relevant forces, such as friction, normal forceand shear force. By force we mean normal force applied to the preventionmechanism at the contact point between outer surface of prevention meansand the material (which is the reaction of the material to the pushingforce applied by the user and the motor torque). The force may thus bethe contact force.

According to an embodiment, the working part comprises at least oneindentation into which the prevention means can retract, i.e. forarranging the prevention means therein. In this embodiment, theprevention means is partially arranged in the indentation when it is inits first position, and essentially fully arranged therein, when theprevention means is in its second position. According to anotherembodiment, the indentation is a groove or a hole in the working part.Such an embodiment is preferably used when the prevention means isarranged on the same level of the working part as the working means,such that the prevention means retracts into the indentation to allowthe working means to process the objects. According to an embodiment,the indentation has a V-shape or a stepped shape profile. By V-shape itis meant that the width of the indentation at its bottom is smaller thanthe width of the indentation near the surface of the working part. Bystepped shape profile it is meant that the width of the indentation isnot uniform but rather it has different widths and the changes in widthare not continuous but sharp. Such stepped shape profile allows onlylimited radial movement of the prevention means (in the form of a ringor partial ring, for example) related to the working part.

This description concerns mainly a surgical burr. However, the sameprinciple is fully applicable to twist drills and saws used in surgery.Thus, the various embodiments and alternatives described herein arefully applicable to the twist drills and saws as also explained in thisdescription. Therefore, the term working means of the surgical burr isequivalent to the term working surface when the surgical twist-drilland/or surgical saw are used. Likewise, the terms material and objectcan be interchanged when it is question of what the device described isaimed to process.

In other embodiments, such as when a saw is used, no indentation isneeded as the prevention means can be arranged on top of the workingpart such that it is essentially parallel to it. Indeed, in such a case,the working surface is for example the teethed side surface of the saw,and the prevention means is arranged to at least partly cover thatsurface when it is in its first position. By covering it is here meantthat when the device is looked at from above or below, the cuttingsurface (the teeth) are not fully visible.

According to an embodiment, the present description relates to thedevice comprising prevention means; attachment means; and a working partcomprising at least one working means (or, at least one working surface)for the processing of a material (or, an object) and at least oneindentation for arranging the prevention means therein. The preventionmeans is configured to protrude from the working part when a forceapplied to the prevention means is less than a predetermined amount offorce, and retract to the at least one indentation when the forceapplied to the prevention means is equal or higher than thepredetermined amount of force.

The different parts of the device can be connected to each other indifferent ways. For example, there might be a prominent part on theinner surface of the prevention means, which rests against theindentation and acts as pivot point. A spring installed at one end ofthe prevention means applies the required force to protrude theprevention means from the indentation to provide protection during useof the device.

According to an embodiment of the invention, the prevention means mayalso have more than two positions, i.e. intermediate positions betweenthe first position and the second position. These intermediate positions(which can be in any discrete number, such as one, two, three, four orfive) are used to control the depth of the cut. Indeed, for example afirst intermediate position allows a depth of 1 μm (micrometer) perrevolution for the cut, while a second intermediate position allows adepth of 2 μm per revolution for the cut, and the third position allowsa depth of 3 μm per revolution for the cut. These positions are selectedby the user with the force applied to the device and thus the force thedevice is pushed against the material under processing and can beachieved with various technical means, such as spring. There may also bedifferent limitation means in the device, that lock the prevention meansinto the selected intermediate position, and a slightly higher force isneeded to overcome the lock and to move to a next position. It is alsopossible to design the device in such a manner that when pressure (i.e.the contact force) is released, the prevention means automaticallyreturns to its first position.

Depending on the flexibility of the prevention means, the retraction tothe indentation might happen in forms of deformation of the (flexible)prevention means, lever type movement of the (rigid) prevention means,or a combination of them (semi-flexible prevention means). Hence, theexistence of a spring (as described below in connection with oneembodiment) might not be crucial when the prevention means is a springitself or is made of an elastomer. The spring may thus be made forexample of silicone, or it may be a canted coil or a wave spring. Inaddition, the prevention means may be configured to have a hook shapedform at the end, to allow only limited radial movement of the preventionmeans in relation to the working part.

The prevention means may be made in one part or it may be made inseveral parts, such as an inner part and an outer part (or several ofeither or both), as explained in more detail below. The shape of theprevention means may also vary, depending on the working surface, forexample. The prevention means may also be in one part while having thesame form as a prevention means in two parts, as the inner and outerparts can be made integral with one another.

In an implementation of the present disclosure, the device is a surgicalburr. The surgical burr comprises a working part comprising at least oneworking means for the processing of a material. The material is selectedfrom a bone, a cartilage, a calcified tissue, a tooth and a foreignobject within a patient body (such as an implant). In an embodiment, thesurgical burr may be a burr suitable for cutting, milling, polishingand/or grinding. For instance, the surgical burr may be used forperforming surgical operations for the treatment of various pathologies,injuries, disabilities, bone misalignments or dental conditions.

In an embodiment, the device, such as the surgical burr, may be attachedto a rotating mechanism using an attachment means. For example, therotating mechanism may be powered by a motor, which may be coupled tothe device using a coupling means, such as a chuck, a bearing and a geararrangement. In one embodiment, the rotating mechanism may provide arotary motion to the device. In another embodiment, the rotatingmechanism may be adapted to provide an oscillatory motion to the device.For example, the rotating mechanism may be associated with a suitablemotion changing mechanism (a gear arrangement) that converts a rotarymotion into the oscillatory motion.

In an embodiment, the working means for processing of the material isselected from a cutting surface or a grinding surface (also calledabrasive surface). Specifically, each configuration of the working partmay process the material differently according to requirement ofoperator of the surgical burr. The working part may also comprise morethan one type of working means, if need be.

In an embodiment, the surgical burr may comprise a working part attachedto a shank. Specifically, the working part is a spherical bodyconfigured for cutting, grinding and shaping of work material such asbones or teeth. Naturally, the working part may also have other shapes,such as cylindrical shape, egg-like shape, pear-like shape, conicalshape etc. The present device is also usable for other materials thanhard tissues, such as wood, metal or ceramics. More specifically, the atleast one working means of the surgical burr may be a protruding or anelevated surface on the spherical body, which may act as a cuttingsurface, a grinding surface or an abrasive surface etc. Further, theworking part may be attached to a shank. The shank is operable to beattached to the rotating mechanism to provide rotary motion to theworking part, through the attachment means designed in for example theshank of the surgical burr. Subsequently, the rotation of the workingpart of the surgical burr enables removal of material from the surfaceof the work material. In an example, the surgical burr may be configuredto rotate in the range of hundreds or thousands (for example1,000-4,000,000) of revolutions per minute for effortless removal ofmaterial from the surface of work material. In an example, the surgicalburr may be used to shape or remove bone to treat conditions of the heador spine.

The prevention means is configured to protrude from the working partwhen a force applied to the prevention means is less than apredetermined amount of force and to retract when the force applied tothe prevention means is equal or higher than the predetermined amount offorce. In an embodiment, the predetermined amount of force is associatedwith (or based on) the composition of a material to be contacted by theworking means for the processing thereof. Specifically, the material (orcomposition thereof) may be hard enough to provide a force (equal orhigher than the predetermined amount of force) when the prevention meansis allowed to contact and press against the object. Therefore, if theprevention means is allowed to contact and press against a materialhaving a soft composition, the prevention means may not retract.Alternatively, if the prevention means is allowed to contact and pressagainst a material having a hard composition, the prevention means mayretract.

In an embodiment, the predetermined amount of force is selected toprevent the processing of a secondary material, when the secondarymaterial is softer than the material. As explained herein above, thesecondary material may include a soft composition. For example, thesecondary material may be soft tissue such as a blood vessel or nervetissue; and the material may be a bone or a tooth. Therefore, the force,exerted on the prevention means upon contact therewith, may be equal toor higher than the predetermined amount of force when the preventionmeans is allowed to contact and pressed against hard tissues such asbone or teeth.

According to an embodiment, the working part of the surgical burr maycome in contact with the material to enable processing thereof when theprevention means retracts, optionally to the at least one indentation.Further, prevention means is operable to at least reduce the surfacecontact between the working part and soft tissues to avoid anyunintended damage to the soft tissues thereof. In an example, the softtissues such as nerves, blood vessels, and so forth may be located nearthe hard tissues such as bones and cartilages in human body. The softtissue to be protected may be also the user's fingers or the material tobe processed may be hard material such as a workpiece.

In an embodiment, the prevention means may comprise at least one outermember and at least one inner member. In yet another embodiment, theprevention means comprises at least one outer part and at least oneinner part, i.e. the inner and outer members are integral with oneanother. Thus, all the various embodiments and designs described withrespect to the inner and outer members apply mutatis mutandis to theinner and outer parts.

In an embodiment, the inner member may be made of an elastomer andarranged in the at least one indentation between the working part andthe outer member. The outer member may be a ring. According to anembodiment, when the device is a surgical burr, the outer member is aring. Further, in such embodiment, the indentation may be a circulargroove in the working part of the burr. Specifically, the indentationmay be a groove in a spherical surface of the surgical burr. Also, aplane of the groove may be tilted at an angle as compared to centralaxis of the shank of the surgical burr, in order to provide protectionall around the working part when it rotates about the axis of rotation.Further, the groove may be designed to limit the radial movement of thering on the spherical surface of the burr. For example, the groove maybe configured to have a V-shape or a stepped shape profile, which mayonly allow limited radial movement of the ring related to the workingpart.

In one embodiment, the ring has an opening arranged to be in contactwith a notch in the working part for preventing the ring to rotate inrelation to the working part. Specifically, core of the burr may beconfigured to have an additional piece of material attached inside agroove. Therefore, such protruding element may prevent the ring torotate in relation to the working part. Furthermore, the notch may bearranged to fit into the opening of the ring. Therefore, the notchrestricts relative movement of the ring to rotate in relation to theworking part. This enables in precluding damage that may be caused bythe relative movement of the ring to the inner member, particularly,elastomeric surface of the inner member. Likewise, the ring may have aprotrusion arranged to be in contact with a notch in the working partfor preventing the ring to rotate in relation to the working part. Stillfurther, a closed ring can be used, where the ring is compressed to aspecific shape and its ends are attached to one another to form a loop.The attaching can be done for example by laser welding.

In an embodiment, the inner member is a spring arranged between theworking part and the outer member, for example in the at least oneindentation. That is, the inner member (for example an elastomer) isconfigured to act as a spring. Specifically, the inner member is adaptedto compress and expand, when subject to or released from equal to ormore than the predetermined amount of force. Further, the dimensions andstiffness or composition of the inner member are selected in such amanner that the outer member protrudes at least partly from the workingpart when the force applied to the prevention means is less than apredetermined amount of force, and the outer member retracts into the atleast one indentation when the force applied to the prevention means isequal or higher than the predetermined amount of force. In anembodiment, the inner member (for example the elastomer) may comprisecuts or slices on an outer surface thereof to provide enough space,which allows compression of the inner member. In another embodiment, theinner member may be a circular canted coil spring. Specifically, suchspring may be closed loop that is stretched to be installed in the atleast one indentation in the working part. In yet another embodiment,the inner member may be a circular wave spring. Furthermore, such springmay be welded to the inside of the at least one indentation in theworking part or to the outer member.

According to an embodiment, the outer member (for example the ring) isconfigured to protect the soft tissues from unintended processing.Specifically, the inner member may undergo compression when the ring ispressed against a hard tissue such as teeth or bones to expose the outersurface of the working part of the surgical burr. Alternatively, theinner member may not undergo compression when the outer member ispressed against the soft tissues to prevent unintended contact betweenthe working part of the surgical burr and the soft tissues.

In another embodiment, the prevention means may comprise an elastomerarranged in multiple indentations in the working part of the surgicalburr. Further, the indentations may be in the form of segments onopposite sides of the surgical burr in which the elastomer may bearranged. The elastomer in the segments is configured to protrude orretract depending upon the force applied thereto. Alternatively, thesurgical burr may have cutting edges in shape of flutes (i.e. theworking means) in the working part of the surgical burr. The elastomermay be arranged in the alternate flutes thereof. Further, the elastomermay retract to the flutes (when subjected equal to or more thanpredetermined amount of force) to expose the cutting edges of thesurgical burr to enable processing.

According to an embodiment, the prevention means is a moving part havingan outer portion and inner portion, and the outer portion is configuredto protrude from the working part to prevent the working surface fromprocessing the material, when the prevention means is in its firstposition. Indeed, in this embodiment, the inner portion is configured toact as a spring, wherein the spring constant is dimensioned so that theouter portion protrudes at least partly from the working part when theforce applied to the prevention means is less than a predeterminedamount of force, and the outer portion retracts into the at least oneindentation when the force applied to the prevention means is equal orhigher than the predetermined amount of force.

In an embodiment, the working means are cutting edges and the preventionmeans comprises a number of flaps, each flap being arranged between twocutting edges. In this case, each flap is arranged, in its firstposition, to push soft tissue away from the cutting edge, thuspreventing the cutting edge from touching the soft tissue. Therefore,each flap is arranged, in its second position, to allow the workingmeans to be in contact with hard tissue.

In another embodiment, the working part of the surgical burr may becylindrical in shape. In this embodiment, the working means are cuttingedges on the cylindrical surface and the prevention means comprises anumber of flaps, each flap being arranged between two cutting edges. Inthis case, each flap is arranged, in its first position, to push softtissue away the cutting edge, and, in its second position, to allow theworking means to be in contact with hard tissue. The flaps can be madefrom metal or plastic, for example from a thin sheet of stainless steel.

Thus, as mentioned above, the surgical burr may be attached to arotating mechanism using the shank attached to the working part.Furthermore, the working part may comprise cutting edges on a surface ofthe working part. Additionally, the prevention means may be arrangedbetween the cutting edges of the working part. Specifically, theprevention means may be resilient flaps arranged between the cuttingedges. More specifically, the resilient flaps may be attached from afirst end using spot or laser welding to the working part. Furthermore,in case of a plastic flaps, the resilient flaps may be attached using anadhesive. Alternatively, the working part may have a slot or similarinto which an end of the flap or a protrusion (such as a rail) at oneend of the flap can be arranged. In operation, the prevention means maypush soft tissue away from the cutting edge, when the force appliedthereto is less than the predetermined amount of force, thus preventingthe cutting edge to come into contact with the soft tissue.Additionally, the prevention means may retract and is pressed againstthe working part when the force applied thereto is equal or higher thanthe predetermined amount of force.

In an embodiment, the prevention means, such as the resilient flaps,arranged between the cutting edges of the surgical burr may have afiller arranged on a second edge of the resilient flap. Specifically,the filler member may be an elastomeric member that may be compresses toallow retraction of the prevention means. Furthermore, the filler membermay prevent accumulation of the processed material behind the resilientflaps. In yet another implementation of the present disclosure, thedevice is a twist-drill. The twist-drill is a cylindrical tool having aworking part comprising at least one working surface for drilling of anobject. Further, the twist-drill may include be attached to a rotatingmechanism using an attachment means (such as, a shank) to enable thetwist-drill for drilling of the object.

In an embodiment, the at least one working surface may be at least onecutting edge in the bottom end, and one flute for drilling of theobject. In another embodiment, when the device is a twist-drill, the atleast one indentation may be a hole in the working part. Specifically,the indentation is a longitudinal hole in the working part in proximityof the cutting edge of the drill bit for arranging the prevention meanstherein. In an embodiment, the indentation may comprise more than onehole in the working part of the drill bit for arranging more than oneprevention means therein.

In an embodiment, the at least one prevention means comprises at leastone outer member and at least one inner member, and the inner member isin the form of a spring. Specifically, the at least one inner member andthe at least one outer member may both be configured to be arranged inthe at least one indentation in the working part (such as, a hole),configured at the bottom end of the twist-drill. In one embodiment, theat least one outer member may look like a hook, i.e. it may have a stemand a hooked tip. Further, the at least one outer member may be mountedwithin the hole. For example, the at least one outer member may includea protruding part or a stop adapted to be received by a recess aroundthe hole, such that at least one outer member does not come out of thehole. Alternatively, the at least one outer member may be coupled to theat least one inner member, and the at least one inner member may befurther coupled to the hole, for example using a suitable adhesive. Theat least one inner member is arranged in the hole between thetwist-drill and the at least one outer member. In an embodiment, the atleast one prevention means of the twist-drill, may include a pair ofholes, each accommodating the at least one inner member and at least oneouter member therein.

According to the embodiment, the inner portion may be a helical spring,and the spring is dimensioned so that the outer portion protrudes atleast partly from the working part when the force applied to theprevention means is less than a predetermined amount of force. Further,the outer portion retracts into the at least one indentation when theforce applied to the prevention means is equal or higher than thepredetermined amount of force. Specifically, the outer portion maycompress the inner portion, when pressed against hard tissues, such asbones, to expose the cutting edges of the twist-drill. Therefore, theouter portion prevents unintended contact between the at least oneworking surface and the soft tissues. Specifically, if the at least oneworking surface comes in contact with the soft tissue (or moved awayfrom the hard tissue), a tip of the outer member may protrude due tolack of predetermined force and thereby prevent damage to the softtissue.

In another aspect, an embodiment of the present disclosure thus providesa twist-drill comprising

at least one prevention means;

attachment means; and

a working part comprising at least one working surface for drilling ofan object;

wherein the at least one prevention means is configured to have

-   -   a first position in which it protrudes from the working part, to        prevent the working surface from drilling the object, when a        force applied to the prevention means is less than a        predetermined amount of force, and

a second position in which it retracts to allow the working surface todrill the object, when the force applied to the prevention means isequal or higher than the predetermined amount of force.

In this embodiment, the working surface is located on a bottom end ofthe drill bit. I.e. the drill bit is attached to a drill from one endand the working surface, in this case cutting edges, are arranged in theother end, i.e. bottom end.

In yet another aspect, an embodiment of the present disclosure providesa saw as mentioned above. Such saw comprises

prevention means;

attachment means; and

a working part comprising at least one working surface for cutting of anobject, in the form of working teeth;

wherein the prevention means is configured to have

a first position in which it protrudes from the working part, to preventthe working surface from cutting the object, when a force applied to theprevention means is less than a predetermined amount of force, and

a second position in which it retracts to allow the working surface tocut the object, when the force applied to the prevention means is equalor higher than the predetermined amount of force.

In yet another implementation of the present disclosure, the device maythus be a saw. Further, the working part of the saw may comprise atleast one working surface for cutting of an object, in form of workingteeth. Furthermore, the working part may be attached to an attachmentmeans, optionally integral with the saw, adapted to be operativelycoupled to a rotating mechanism to provide oscillatory motion to thesaw.

Optionally, the saw is selected from a reciprocating saw blade, acircular saw blade and an oscillating saw blade. In an embodiment, thesaw may be an oscillating saw blade or a reciprocating saw blade. Theoscillating saw blade may comprise an indentation on the surfacethereof. Further, the prevention means may be arranged in theindentation on a surface, of the oscillating saw blade, adjacent toworking teeth. Furthermore, an inner member of the prevention means maybe a spring that may be placed in the indentation to control protrusionand retraction of an outer member of the prevention means with respectto the indentation. The spring may be thus made of an elastomeric partor it may be a traditional metallic spring. In an embodiment, the outermember may be a comb like structure configured to protrude in betweenworking teeth of the oscillating saw blade. The outer member isconfigured to prevent unintended contact between the working teeth andsoft tissues. Further, the outer member of the prevention means mayretract to the indentation, when the outer member is subject to hardtissue, and thereby exposing the working teeth of the oscillating sawblade to the hard tissue. In these embodiments, it is also possible todesign the device without indentations on the working part, as has beendescribed above.

According to an embodiment, the saw may be a circular saw blade.Further, the circular saw blade may include a central mounting hole,adapted to be operatively coupled to a rotating mechanism, using anattachment means to obtain rotary motion. Further, prevention means maybe arranged in at least one indentation present on either one or bothsides of the circular saw blade, and/or in the middle of the circularsaw blade. The prevention means may comprise for example two separatesemi-circular outer members on at least one side of the circular sawblade. The semi-circular outer members are configured to protrude fromthe lateral surface of the circular saw blade, i.e. to at least partlycover the sharp edges of the working teeth.

In one embodiment, the prevention means also includes an inner member,such as a pair of elliptical spring members, positioned between theouter members on at least one side of the circular saw blade. Thesprings may be configured to push the moving part(s) outwards or pullingit (them) inwards. For example, at the high rotations, centrifugalforces are so high that the force required to retract the moving partsinside the indentation is too high for practical purposes. In this casethe tension spring is needed to reduce the force at the high operatingspeed. Specifically, the semi-circular outer members on each side of thecutting disk may have a common inner member to control the protrusionand retraction of the outer members with respect to the indentation.Moreover, the protrusion and retraction of the outer members withrespect to each quadrant is configured separately. Thus, the circularsaw blade is operable to perform cutting of the object andsimultaneously protect the secondary object surrounding the object (forexample soft tissue adjacent to hard tissue or user's finger or hand).Additionally, the semi-circular outer members of the prevention meansmay be supported by support tabs configured in the indentations on thesurface of the circular saw blade. The number of support tabs can be forexample one, two, three, four, five or six. Each support tab typicallycomprises a head and a shaft and they are arranged by press fitting intothe holes arranged in the circular saw blade. Further, the common innermember on each side of the circular saw blade may be supported betweenthe semi-circular outer members with help of the support tabs, morespecifically the shafts of the support tabs. Therefore, the preventionmeans on each side of the circular saw blade may be configured toprotect alternate quadrants of the working teeth from unintended contactwith the secondary object.

The arrangement of working teeth described above can have differentstructures. For example, the working teeth can be divided into four setsof working teeth. These sets of working teeth can protrude from a middleplane, in opposite directions, depending on the position of the movingpart adjacent to it. The number of working teeth sets may depend on thenumber of moving parts. Typically, the circular saw blade is configuredto be capable of making cuts as wide as the blade width. If the movingparts are placed in a same plane, the cutting penetration is limited asthe moving parts do not have the capability of removing material aheadof them.

As has been described, the present device can have various forms. Oneadditional possible form is a reciprocating saw blade, in which thecutting action is achieved through a push-and-pull (“reciprocating”)motion of the blade. The blades of such reciprocating saw may bearranged in any suitable manner, for example as describe above inconnection with the oscillating saw blade. A still further possibilityis any kind of burr, having various forms, some of which are illustratedbelow in connection with the Figures.

According to an embodiment, the object to be processed by the device (ofthe present disclosure) may include different compositions. For example,the object may be made of a material selected from a bone, a tooth,cartilage, a calcified tissue, a crust, a wood, a metal, a plastic.Specifically, the device of the present disclosure may be operable forprocessing of object in carpentry, metal machining and plasticsindustry. Further, the crust may be a hardened layer, a deposit or acoating on the surface of an object. The device may be used for theprocessing of the crust on the surface of the object. Additionally, thedevice may be used in large-scale applications such as carpentry andmetal machining to achieve better control for handheld devices, targetedprocessing and minimal damage of objects such as wooden planks, metalsheets, and so forth.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1, illustrated is a perspective view of a surgicalburr 100, in accordance with an embodiment of the present disclosure. Asshown, the surgical burr 100 comprises a working part 102 having atleast one working means 104. Furthermore, the working part 102 isspherical in shape. The working part 102 is attached to a shank 106. Theshank 106 comprises attachment means 108 at its other end, to allow theshank 106 to receive the rotary motion. Further, the working part 102includes a prevention means 110. Moreover, the prevention means 110includes an outer member 112, in this embodiment a ring. The surgicalburr 100 is a cutting burr and the working means 104 are cutting edges.Furthermore, the axis A illustrates the axis for rotational motion ofthe surgical burr 100.

Referring to FIG. 2, illustrated is an exploded view of the surgicalburr 100 of FIG. 1, in accordance with an embodiment of the presentdisclosure. As shown, the working part 102 comprises at least oneindentation 202 for arranging the prevention means therein. Theprevention means comprises the outer member 112 and the inner member204. Optionally, the inner member 204 is made of an elastomer andarranged in the at least one indentation 202 between the working part102 and the outer member 112. The inner member 204 includes cuts 206 onan outer surface of the inner member 204.

Referring to FIG. 3, illustrated is a bottom view of the surgical burr100, in accordance with an embodiment of the present disclosure. Asshown, the working part 102 comprises working means 104, such as thecutting edges 105. Furthermore, the prevention means 110 is arranged onthe working part 102.

Referring to FIGS. 4 and 5, illustrated are rear and front views of thesurgical burr 100, in accordance with an embodiment of the presentdisclosure. The surgical burr 100 comprises the working part 102comprising at least one working means, such as the working means 104.Furthermore, the prevention means 110 is arranged on the working part102. The working part 102 is attached to the shank 106. FIG. 5 alsoshows an angle α. Indeed, a plane of the groove is tilted at angle α ascompared to axis of rotation A of the surgical burr.

Referring to FIG. 6, illustrated is a cross-sectional view of thesurgical burr 100 of FIG. 5 along B-B′, in accordance with an embodimentof the present disclosure. As shown, the surgical burr 100 includes anindentation 202 present along surface of working part 102 of thesurgical burr 100. The indentation 202 includes a step shapedconfiguration. Further, the step shaped indentation 202 is shown toreceive prevention means, particularly, an outer member 112 and an innermember 204, therein.

Referring to FIG. 7, illustrates is an enlarged view of an encircledsection D of the surgical burr 100 of FIG. 6, in accordance with anembodiment of the present disclosure. As shown, the indentation 202includes a stepped shape configuration shown to receive preventionmeans, particularly, an outer member 112 and an inner member 204,therein. Furthermore, the stepped shape configuration only allowslimited radial movement of the outer member 112 related to the workingpart 102. In addition, the stepped shape configuration allows limitedcompression of the inner member 204.

Referring to FIGS. 8, 9 and 10, illustrated are cross-sectional views ofthe surgical burr 100 of FIG. 5 along C-C′, in accordance with variousembodiment of the present disclosure. As shown, the surgical burrcomprises a working part 102. Further, the working part 102 includes aprevention means 110. The prevention means comprises the outer member112 and the inner member 204. As shown in FIG. 8, the inner member 204is made of an elastomer. The inner member 204 is arranged in anindentation between the core 203 of the working part 102 and the outermember 112. Furthermore, the inner member 204 includes cuts 206 arrangedon the outer surface of the inner member 204 to allow compressionthereof. As shown in FIG. 9, the inner member 204 is a circular cantedcoil spring. Furthermore in FIG. 10, the inner member 204 is a circularwave spring. FIGS. 8, 9 and 10 also show a laser weld, indicated withreference number 205.

Referring to FIG. 11, illustrated is a perspective view of a surgicalburr 1100, in accordance with an embodiment of the present disclosure.As shown, the surgical burr 1100 comprises a working part 1102 having atleast one working means, such as a working means 1104. Furthermore, theworking part 1102 is spherical in shape. The working part 1102 isattached to a shank 1106. The shank 1106 comprises attachment means 1108at its other end, to allow the shank 1106 to receive the rotary motion.Further, the working part 1102 includes a prevention means 1110.Moreover, the prevention means 1110 includes an outer member 1112, suchas a ring. The outer member 1112 includes an opening 1114 arranged to bein contact with a notch 1116 in the working part 1102. The surgical burr1100 is a grinding burr and the working means 1104 is a working surface.Furthermore, the axis E illustrates the axis for rotational motion ofthe surgical burr 1100.

Referring to FIG. 12, illustrated is cross-sectional view of thesurgical burr 1100 of FIG. 11 along F-F′, in accordance with anembodiment of the present disclosure. As shown, the prevention means1110 includes the outer member 1112 and an inner member 1202. The innermember 1202 includes cuts 1204 on an outer surface of the inner member1202. The inner member 1202 is arranged in an indentation between thecore 1206 of the working part 1102 and the outer member 1112. Moreover,the notch 1116 is arranged to be in contact with the opening 1114 in theouter member 1112 of the prevention means 1110.

Referring to FIGS. 13 to 16, illustrated are schematic illustrations ofthe surgical burr 100 of FIG. 1 in utilized states, in accordance withan embodiment of the present disclosure. Optionally, the surgical burr100 of FIG. 11 may be utilized in a similar manner. As shown, thesurgical burr 100 includes the prevention means 110 and the working part102, which working part 102 has a working means 104. The preventionmeans 110 is configured to protrude when a force applied to theprevention means 110 by a secondary material (such as soft tissue) 1302(as shown in FIG. 14) is less than a predetermined amount of force.Therefore, the secondary material 1302 is not contacted by the workingmeans 104 as shown by the distance P therebetween.

Referring now to FIGS. 15 and 16, the prevention means 110 is configuredto retract to an indentation 202 when the force, applied to theprevention means 110 by a material (such as hard tissue) 1602 (as shownin FIG. 16), is equal or higher than a predetermined amount of force.This exposes the working means 104 of the working part 102 to thematerial 1602.

Referring to FIG. 17, illustrated is a perspective view of a surgicalburr 1700, in accordance with an embodiment of the present disclosure.As shown, the surgical burr 1700 comprises a working part 1702 having atleast one working means, such as a working means 1704. Furthermore, theworking part 1702 is cylindrical in shape. The working part 1702 isattached to a shank 1706. The shank 1706 comprises attachment means 1708at its other end, to allow the shank 1706 to receive the rotary motion.Further, the working part 1702 includes resilient flaps as a preventionmeans, such as a resilient flap 1710. Furthermore, the resilient flaps,such as a resilient flap 1710, are attached to the working part 1702from a first end 1712 thereof using spot welding, laser welding or anadhesive. Additionally, optionally, the resilient flaps, such as theresilient flap 1710, may have a filler, such as a filler 1714, attachedto a second end 1716 of the resilient flap 1710. The surgical burr 1700is a cutting burr and the working means 1704 are cutting edges.

Referring to FIG. 18, illustrated is an exploded view of the surgicalburr 1700, in accordance with an embodiment of the present disclosure.The working part 1702 of the surgical burr 1700 comprises cutting edgesas working means 1704. Furthermore, the axis G illustrates the axis forrotational motion of the surgical burr 1700. Additionally, the surgicalburr 1700 comprises resilient flaps as prevention means, such as theresilient flap 1710. The resilient flaps, such as the resilient flap1710, are attached to the working part 1702 from a first end thereof,such as the first end 1712 of the resilient flap 1710. Furthermore, thefiller, such as the filler 1714, is attached to the second end of theresilient flaps, such as the second end 1716 of the resilient flap 1710.

Referring to FIG. 19, illustrated is a bottom view of the surgical burr1700, in accordance with an embodiment of the present disclosure. Asshown, the working part 1702 comprises working means 1704, such as thecutting edges. Furthermore, the resilient flaps, such as the resilientflap 1710 is arranged on the working part 1702. Additionally, a filler,such as the filler 1714 is arranged between the resilient flaps, such asthe resilient flap 1710, and the working part 1702.

Referring to FIGS. 20 and 21, illustrated are perspective views of asurgical burr, in accordance with different embodiments of the presentdisclosure. As shown, a surgical burr 2000 includes a cutting edge 2002in shape of flute 2003 as working means on the working part 2004 (havinga working surface 2005) of the device 2000. The surgical burr 2000includes prevention means, which includes a pair of elastomer segments2006 and 2007 on opposite sides of a working part 2004 of the device2000. The elastomer segments 2006 and 2007 are configured to protrude orretract depending upon the force applied thereto. Further, as shown inFIG. 21, a device 2100 includes cutting edges 2101 and 2102 in shape offlutes 2103 and 2105 on the working part 2104 (having a working surface2108) of the surgical burr 2100. Further, the surgical burr 2100 alsoincludes prevention means, such as elastomers 2106 and 2107 arranged inalternate flutes on the working part 2104. In addition, the devices 2000and 2100 are shown to include attachment means 2010 and 2110, integralwith the burrs, adapted to be operatively coupled to a rotatingmechanism (not shown).

FIGS. 22 and 23 show yet another embodiment of a device according to thepresent disclosure. In FIG. 22, the device 2200 comprises a working part2202 comprising a working surface 2205, prevention means 2204 and inindentation 2206 into which the prevention means 2204 may enter.Furthermore, the device comprises a shank 2212 and a spring 2208 forapplying a force to the prevention means 2204. The rotation axis H ofthe device is also indicated. In FIG. 23, the device 2200 is shown as across-section from FIG. 22, and it can be seen that the prevention means2204 has a hook shape 2304 at its end and a prominent part 2302 at itsother end. The spring 2208 surrounds the shaft.

Referring to FIG. 24, illustrated is a perspective view of a twist-drill2400, in accordance with an embodiment of the present disclosure. Asshown, the device 2400 includes a working part 2402, having at least oneworking surface, such as the working surface 2405 having cutting edges2403 and flutes 2404. The twist-drill 2400 also includes at least oneprevention means, such as the prevention means 2406. In addition, thetwist-drill 2400 is shown to include an attachment means 2401, integralwith the drill bit, adapted to be operatively coupled to a drill device(not shown). The rotation axis I of the device is also indicated.

Referring to FIG. 25, illustrated is a cross-sectional view of thetwist-drill 2400 of FIG. 24, in accordance with an embodiment of thepresent disclosure. As shown, an inner member 2502 of the preventionmeans 2406 is arranged between the working part (2402, as shown in FIG.24) and an outer member 2504 of the prevention means 2406.

Referring to FIG. 26, illustrated is a front view of an oscillating sawblade 2600, in accordance with an embodiment of the present disclosure.As shown, the oscillating saw blade 2600 includes a working part 2602having working teeth 2604 as the working surface and prevention means2606 arranged in an indentation 2608 present on a surface of the device2600. The prevention means 2606 includes an outer member 2610 and aninner member 2612. The protrusion and retraction of the outer member2610 is controlled by the inner member 2612 of the prevention means2606. Also, the device 2600 is shown to include an attachment means2620, integral with the oscillating saw blade, adapted to be operativelycoupled to an oscillating mechanism (not shown).

Referring to FIG. 27, illustrated is a perspective view of a circularsaw 2700, associated with a cutting disk, in accordance with anembodiment of the present disclosure. As shown, the saw 2700 includes acircular saw blade 2702 having working teeth 2704 as the workingsurface. The saw 2700 also includes prevention means 2706 on each sideof the circular saw blade 2702. The prevention means 2706 includes twosemi-circular outer members at each side of the circular saw blade 2702,depicted as outer members 2710 and 2712, and a common inner member 2718arranged in an indentation 2720 on a surface of the circular saw blade2702. The outer members 2710 and 2712 are supported with the help ofsupport tabs 2730 and 2732, respectively. Further, the common innermembers 2718 supported with the help of additional support tabs 2740 and2742. Also, the saw 2700 is shown to include an attachment means 2750,integral with the circular saw blade 2702, adapted to be operativelycoupled to a rotating mechanism (not shown). The rotation axis 3 of thedevice is also indicated.

Referring to FIG. 28, illustrated is a side view of the saw 2700 of FIG.27, in accordance with an embodiment of the present disclosure. Asshown, the saw 2700 has two sides 2802 and 2804. Further, the outermembers 2710 and 2712 are shown to be arranged on the side 2802, and anouter member 2714 is shown to be arranged on the side 2804.

Referring to FIG. 29, illustrated is a cross-sectional view of asurgical round burr perpendicular to central axis of the burr. The burrincludes flutes 122 and 123 having rake surfaces 132 and 133 andclearance surfaces 142 and 143. The rake and clearance surfaces of eachflute meet to form cutting edges 152 and 153 that extends along thelength of the flute.

Modifications to embodiments of the present disclosure described in theforegoing are possible without departing from the scope of the presentdisclosure as defined by the accompanying claims. Expressions such as“including”, “comprising”, “incorporating”, “have”, “is” used todescribe and claim the present disclosure are intended to be construedin a non-exclusive manner, namely allowing for items, components orelements not explicitly described also to be present. Reference to thesingular is also to be construed to relate to the plural.

What is claimed is:
 1. A method comprising: processing a first materialusing a working part comprising a working means and a prevention means;and using the prevention means to simultaneously prevent damage to asecond material adjacent the first material.
 2. The method of claim 1,wherein the prevention means moves with the working means.
 3. The methodof claim 1, wherein processing the first material comprises one or moreof cutting, grinding, milling, drilling, polishing, or sawing.
 4. Themethod of claim 1, wherein the first material is selected from one ormore of a bone, a cartilage, a calcified tissue, a tooth, or a foreignobject within a patient body.
 5. The method of claim 1, wherein usingthe prevention means to simultaneously prevent damage to the secondmaterial comprises using the prevention means to at least reduce surfacecontact between the working means and the second material.
 6. The methodof claim 5, wherein using the prevention means to at least reducesurface contact between the working means and the second materialcomprises using the prevention means to push the second material awayfrom the working means.
 7. The method of claim 1, wherein using theprevention means to simultaneously prevent damage to the second materialcomprises arranging the prevention means to provide protection allaround the working part while processing the first material.
 8. Themethod of claim 7, wherein arranging the prevention means to provideprotection all around the working part comprises using the preventionmeans to at least partially cover the working means.
 9. The method ofclaim 7, wherein arranging the prevention means to provide protectionall around the working part comprises tilting the prevention means at anangle to an axis of rotation of the working part to provide protectionall around the working part as the working part rotates about the axisof rotation.
 10. The method of claim 1, wherein the prevention meanscomprises a resilient part attached to a surface of the working part.11. The method of claim 1, wherein the prevention means comprises arigid material.
 12. The method of claim 1, wherein the prevention meanscomprises at least an inner member and at least an outer member, whereinthe inner member is arranged between the working part and the outermember.
 13. The method of claim 12, wherein the outer member is a movingpart.
 14. The method of claim 1, wherein the prevention means comprisesa moving part comprising at least an inner member and at least an outermember, wherein the inner member is arranged between the working partand the outer member.
 15. The method of claim 14, wherein the innermember and outer member are integral with the moving part.
 16. Themethod of claim 1, comprising arranging the prevention means inintermediate positions between the first and second position based on aforce applied to the working part to allow for different processingdepths of the first material.
 17. The method of claim 1, wherein thesecond material is softer than the first material.
 18. A method ofprocessing a first material comprising: arranging a prevention means ina first position to prevent a working part comprising a working meansand the prevention means from processing first and second materials; andarranging the prevention means in a second position to allow the workingmeans to process the first material while the prevention meanssimultaneously prevents damage to a second material adjacent the firstmaterial.
 19. The method of claim 18, wherein the prevention means moveswith the working means.
 20. The method of claim 18, wherein arrangingthe prevention means in the first position comprises applying a forceless than the predetermined force to the prevention means to prevent theworking means from contacting the first and second materials.
 21. Themethod of claim 18, wherein arranging the prevention means in the secondposition comprises applying a predetermined force to the preventionmeans to allow the working means to contact the first material.
 22. Themethod of claim 18, comprising arranging the prevention means inintermediate positions between the first and second position based on aforce applied to the working part to allow for different processingdepths of the first material.
 23. The method of claim 18, whereinprocessing the first material comprises one or more of cutting,grinding, milling, drilling, polishing, or sawing.
 24. The method ofclaim 18, wherein the first material is selected from one or more of abone, a cartilage, a calcified tissue, a tooth, or a foreign objectwithin a patient body.
 25. The method of claim 18, wherein arranging theprevention means in the second position comprises arranging theprevention means to at least reduce surface contact between the workingmeans and the second material.
 26. The method of claim 25, whereinarranging the prevention means to reduce surface contact between theworking means and the second material comprises arranging the preventionmeans to push the second material away from the working means.
 27. Themethod of claim 18, wherein arranging the prevention means in a secondposition to allow the working means to process the first material whilethe prevention means simultaneously prevents damage to a second materialadjacent the first material comprises arranging the prevention means toprovide protection all around the working part while processing thefirst material.
 28. The method of claim 27, wherein arranging theprevention means to provide protection all around the working partcomprises tilting the prevention means at an angle to an axis ofrotation of the working part to provide protection all around theworking part as the working part rotates about the axis of rotation. 29.The method of claim 18, wherein the prevention means comprises aresilient part attached to a surface of the working part.
 30. The methodof claim 18, wherein the prevention means comprises a rigid material.31. The method of claim 18, wherein the prevention means comprises atleast an inner member and at least an outer member, wherein the innermember is arranged between the working part and the outer member. 32.The method of claim 31, wherein the outer member is a moving part. 33.The method of claim 18, wherein the prevention means comprises a movingpart comprising at least an inner member and at least an outer member,wherein the inner member is arranged between the working part and theouter member.
 34. The method of claim 33, wherein the inner member andouter member are integral with the moving part.
 35. The method of claim18, wherein the prevention means comprises at least an inner member andat least an outer member, wherein the inner member is arranged betweenthe working part and the outer member.
 36. The method of claim 18,wherein the second material is softer than the first material.